日本の湿原（8）深泥池 第2部

摘要

Mire vegetation of the Mizorogaike Pond established on the large floating peat mat. Microtopographydeveloped on the surface of the peat mat. Hummocks distribute on the flat peat surface and the area of hummocksexperiences short period of inundation. Peat surface showed oxic and anoxic changes corresponding to the seasonalchanges of water table. Peat surface is anoxic during the inundated season and the surface peat is oxic when watertable becomes lower than the peat surface. However, just after the emergence of peat surface to the atmosphere, peatsurface temporarily becomes extremely anoxic because of the intensive consumption of supplied oxygen by micro-organisms in peat. Redox potential of peat surface becomes higher at the site that experiences longer period ofsurface emergence. Thus evident gradient of redox potential appears on the peat surface in September and Octoberand plant species distributed on the gradient of redox environment according to their adaptation to soil environment.High spatial variability of peat surface environment corresponding to the slight difference of elevation could sustainthe high species richness in mire vegetation. Mizorogaike pond is located on the middle of the urbanized area andthen the mire experiences high risk of disturbance by human activity. Appropriate management of the mire includingsurrounding catchment area is necessary for the conservation of Mizorogaike Pond.